Liver-cell patterning Lab Chip: mimicking the morphology of liver lobule tissue

Abstract

A lobule-mimetic cell-patterning technique for on-chip reconstruction of centimetre-scale liver tissue of heterogeneous hepatic and endothelial cells via an enhanced field-induced dielectrophoresis (DEP) trap is demonstrated and reported. By mimicking the basic morphology of liver tissue, the classic hepatic lobule, the lobule-mimetic-stellate-electrodes array was designed for cell patterning. Through DEP manipulation, well-defined and enhanced spatial electric field gradients were created for in-parallel manipulation of massive individual cells. With this liver-cell patterning labchip design, the original randomly distributed hepatic and endothelial cells inside the microfluidic chamber can be manipulated separately and aligned into the desired pattern that mimicks the morphology of liver lobule tissue. Experimental results showed that both hepatic and endothelial cells were orderly guided, snared, and aligned along the field-induced orientation to form the lobule-mimetic pattern. About 95% cell viability of hepatic and endothelial cells was also observed after cell-patterning demonstration via a fluorescent assay technique. The liver function of CYP450-1A1 enzyme activity showed an 80% enhancement for our engineered liver tissue (HepG2+HUVECs) compared to the non-patterned pure HepG2 for two-day culturing.

Cell Patterning for Liver Tissue Engineering via Dielectrophoretic Mechanisms

“…However, recently, Ho and other researchers have made some modifications in the microelectrode arrangement to achieve three-dimensional liver cell patterning by generating a vertical DEP force, as shown in Figure 5a [28]. In addition, they also made some changes to the liver-mimetic microelectrode design, which consists of two independent electrodes (Figure 5b).…”

“…Both horizontal and vertical p-DEP have been proven to successfully pattern hepatocytes and endothelial cells according to designed microelectrodes, closely mimicking the morphology of real liver tissue [28,74]. In early microelectrode designs, horizontal DEP forces were generated by two concentric electrodes placed on the same plane, identified as odd-ring and even-ring, which were subjected to an AC voltage.…”

“…( e ) Soft lithography to fabricate hepatocytes micropatterning in a multiwell format [27]. ( f ) Microelectrode for active liver cell patterning via DEP mechanism [28]. Reproduced with permission.…”

Separation and assisted patterning of hippocampal neurons from glial cells using positive dielectrophoresis

“…One of the observed limitations of this technique is the morphological damage to separated cells, such as processes being torn-off from neuron bodies. Dielectrophoresis (DEP) has also been applied to separate particles and biological cells (Gupta et al 2012;Ho et al 2013;Li et al 2014). For instance, polystyrene and latex beads (Li et al 2014), rat embryonic cortical neurons (Yu et al 2004) and human liver cells and endothelial cells (Ho et al 2013) were all successfully manipulated by DEP with planar electrode arrays.…”

Recapitulation of microtissue models connected with real-time readout systems via 3D printing technology

“…Currently, in vitro microtissue devices are emerging as alternatives to animal or conventional cell culture studies (2). Such devices can recapitulate human tissue microenvironments and their fundamental functional units, including the contractile laminar tissue layers of cardiac and skeletal muscles (2)(3)(4)(5), alveolar-capillary interface of a lung (6), villi of intestines (7), lobules of a liver (8), or proximal tubules of the kidney (9). These devices are developed based on attempts to mimic native cellular arrangements and original mechanical movements, and the fabrication of the devices is carried out through microfabrication and microfluidic technologies.…”